The present invention relates to a brake assembly operable to apply an adjustable braking force to an elongate strip of work material movable longitudinally along a fixed path.
The brake assembly of the present invention is specifically designed for use in conjunction with a feeding mechanism employed to feed a continuous strip having electric terminals uniformly spaced along the strip in step-by-step movement to a die and punch mechanism where the terminals are severed from the strip and crimped upon the end of an electrical conductor. Such feed mechanisms are well known in the art, one example of such a feed mechanism being disclosed in U.S. Pat. No. 3,977,587.
In the feed mechanism shown in U.S. Pat. No. 3,977,587, the pins project a rachet tooth-like feeding lever 38 driven in reciprocatory movement along the feed path. The forward end of the rachet tooth is a flat surface which projects into driving engagement with a drive pin to positively drive the pin, and the terminal strip engaged with the pin, forwardly upon forward movement of the rachet. During its rearward stroke, a rearwardly inclined cam surface on the rachet slides beneath the next following drive pin, and a torsion spring then biases the rachet tooth back upwardly so that its flat forward surface will engage and drive this last pin during the next forward working stroke of the rachet.
Proper operation of a feed mechanism of this type relies upon minimal friction between the pins and the pin carrying chain and the pins and cam surface on the rachet tooth and proper adjustment of the rachet return spring. If these conditions are not maintained, the system can bind or jam on the return stroke of the rachet, and cause the strip to be fed in a reverse direction during the return stroke of the feed rachet. This can result in misalignment between terminals on the strip and the crimping die or in severe cases result in no feeding of the strip at all. U.S. Pat. No. 3,977,587 discloses a spring biased wedging cam which will resist reverse movement of the terminal strip while applying a relatively low friction braking action to forward movement of the strip.
The overall crimping apparatus is so designed that the crimping dies may be readily interchanged to enable the mechanism to operate upon different types of terminals. In that the spacing between the pin receiving bores of the carrier strip normally is the same for many different varieties of terminals, setup of the feed mechanism normally does not require any change when production is shifted from one type of terminal to another. However, carrier strip thickness can vary between different types of terminals, and the friction or one-way brake mechanism of the type disclosed in U.S. Pat. No. 3,977,587 typically is set up to handle strips of a single specific thickness.
The present invention is directed to a brake assembly for use in conjunction with feed systems of the general type referred to above which may be readily adjusted to regulate the braking force applied in a simple and efficient manner.